1. Field
Embodiments of the present invention relate to a circuit board and a method of manufacturing the same.
2. Description of the Related Art
In order to deal with a light weight, a small size, a high speed, a multiple functions, and high performance of electronic appliances, multi-layered substrate techniques in which a plurality of interconnection layers are formed on a printed circuit board (PCB) are developed, and further, a technique of mounting electronic components such as an active device or a passive device into a multi-layered substrate is also developed.
Meanwhile, one of important tasks in a multi-layered substrate field may be that built-in electronic components effectively transmit and receive a signal including a voltage or current to/from an external circuit or other devices.
In addition, as tendency for high performance of electronic components, a small size and thinning of electronic components and electronic components-built-in substrate is intensified, in order to mount small electronic components into a smaller and thinner substrate and connect external electrodes of the electronic components to the outside, improvement in integrity of a circuit pattern is necessarily needed.
Meanwhile, as the electronic components-built-in substrate is further thinned, a bending phenomenon of the substrate becomes a serious problem. Such a bending phenomenon may be referred to as warpage, which becomes serious as the electronic components-built-in substrate is formed of various materials having different thermal expansion coefficients.
Document 1 cited below discloses a multi-layered substrate constituted by an insulating layer formed on a glass ceramic material only, and Document 2 cited below discloses a conventional multi-layered substrate in which a core substrate is formed by coating or impregnating a glass core or a glass fiber with resin.
However, when the insulating layer is implemented by the glass ceramic material only like in Document 1, since a process of processing a via and a circuit pattern is very difficult, it is difficult to implement a fine and highly integrated circuit pattern, and it is difficult to secure adhesion reliability between layers.
In addition, even in the case of a core in which the glass core or glass fiber is impregnated with resin like in Patent Document 2, sufficient strength cannot be secured to cause limitation in reduction of warpage.